Abstract
<title>Abstract</title> <p>Manipulating intermolecular electron transport at the molecular scale is essential for advancing molecular electronics. Herein, we report light-gated intermolecular non-covalent conductive pathways through π-π supramolecular junctions featuring donor-acceptor Stenhouse adducts (DASAs), investigated using scanning tunnelling microscope-break junction (STM-BJ) technique. DASAs were functionalized with thiol anchoring sites positioned on the electron-withdrawing or electron-donating moieties, designated as D1, D2 and D3, respectively. Owing to their intermolecular π-π interactions, homo-junctions (D1-D1, D2-D2 and D3-D3) form spontaneously between two identical DASA molecules. These junctions are disrupted by the light-induced linear-to-cyclic isomerization of DASAs. In contrast, hetero-junctions (D1-D3) assemble between two distinct DASAs and can be orthogonally controlled by varying the irradiation wavelength. Specifically, 535 nm light selectively triggers the linear-to-cyclic isomerization of D3, yielding D1-D1 homo-junctions. 690 nm light induces isomerization of D1, producing D3-D3 homo-junctions. 635 nm light simultaneously isomerizes both DASAs, completely disrupting the supramolecular junctions and causing the conductance signals to vanish. This work demonstrates multi-state orthogonal control over intermolecular electron transport pathways, enabling orthogonally photogated conductance switching and providing a strategy toward reconfigurable molecular logic devices with unprecedented operational complexity.</p>